It is a well known skill to coat a color layer on a flat surface of a non-metallic object, such as plastic, rubber, foam rubber, fiber glass and carbon fiber by gluing a transparent plastic thin film having color figure pre-printed thereon onto the flat surface. The drawback of such coating method is well known too, that the plastic thin film can be lift over easily.
Mold printing is another conventional method to put color on a flat plastic surface. To print a color figure on a plastic surface, the figure must be first printed on a sticker. The sticker is pre-placed in the plastic injection mold. While injection, the paper of the sticker will be dissolved by the heat and the color figure will be firmly attach on the plastic surface. However, this mold printing method can only be applied on a flat or circular surface. For an irregular and undulate surface, the color figure would be damaged due to the wrinkles formed thereon.
Gold ironing is another common method of providing figure on a flat plastic or metallic surface. A figure made of metallic ink foil must be pre-attached on a paper, pressure and heat must be applied on the paper for ironing the metallic ink foil on the plastic or metallic surface. This method is also limited to apply on a flat surface. Moreover, the surface of a plastic object may be depressed and stamped to form a sunken area.
Nowadays, most of the ornamental designs of products contain curve and undulate surface, but we can only provide simple decorating figure on those flat surfaces by means of the conventional printing method mentioned above. Therefore, most of the merchandises can merely be designed with single color or simple combination of two to three colors. In fact, at the time of this invention, no product can provide full color picture, drawing or printing all over the entire surface thereof like the paper printing does. Moreover, more and more products are made of more than one materials. No present technology teaches a relatively low cost and simple process to continuously provide a full color picture, drawing or printing across an uneven surface constituted by two different materials, such as foam rubber and plastic.